We develop a theory of policy making that examines when policy sabotage—that is, the deliberate choice by an opposition party to interfere the implementation of a policy—can be an effective electoral strategy, even if rational voters can see that it is happening.In our model, a potential saboteur chooses whether to sabotage an incumbent's policy by blocking its successful implementation. Following this decision, a voter decides whether to retain the incumbent, who is of unknown quality, or to select a challenger.We find that the incentives for sabotage are broadly shaped by the underlying popularity of the incumbent—it is most attractive when an incumbent is somewhat unpopular.If so, sabotage may decrease the probability the incumbent is reelected, even though sabotage is observable to the voter. We illustrate our theory with the implementation of the Affordable Care Act since its passage in 2010.